#include <iostream>
#include <stdio.h>
using namespace std;
int main()
{
	double r;
	while(cin>>r){
		double v;
		v=4.0*3.1415926*r*r*r/3.0;
		int vv;
		vv=(int)(v+0.5);
		cout<<vv<<endl;
	}
	
}
